Method of burning explosive gaseous mixtures.



C. E. LUCKE.

METHOD OF BURNING EXPLOSIVE GASEOUS MIXTURES.

APPLICATION FILED SEPT-21.1912.

Id; 9 l %fi% Patented July 13, 1915.

A ttest: m I ntor: 4. i

To all whom it may concern:

CHARLES E. Lucxn, or NEW Yonx, N..Y., ASSIGNOR 'ro GAS AND on.COMBUSTION COMPANY, or NEW YoRK, N. Y., A CORPOBATION. or DELAWARE' IMETHOD OFIBURNING ExrLosIvE eAsEoUs mrxrunn's.

maaaea.

. Be it known that I, CHARLES E. LUGKE, a

citizen of the United States, residing at New'York city, in the countyofNew York and State of New York, have invented certain new. and usefulImprovements in Methods of Burning Explosive Gaseous Mixtures, fullydescribed and represented in the following specification and theaccompanying drawings, forming a part of the same.-

This invention relates to a method of burning explosive gaseous mixturescontinuously or non-explosively as distinguished dustrial value becauseof its great e'fliciency due to the minimum amount and Weight ofproducts of combustion per unitfof heat de veloped, and becauseof thehigh temperature attained. V

The object of the present invention is genorally to develop thepossibilities of continuous combustion of such explosive mixtures incertain directions beyond what has heretofore been accomplished, and -todo this in such a Wayv as to give great range of control I andadaptability, with freedom from liability of the combustioncommunicating back to the source of supply of the mixture.

vF or the continuous and localized combusr 'tion of explosive gaseousmixtures-two conditions must be realized;first, preventionof back flash,or communication of flame.

through the advancing mixture toward the source of supply; and, second,prevention of blow-ofl, or the carrying away. of :the

- flame and dissipating:ordilution of-the' mixture in'space,-which willusually occur when the velocity of the'mixture at the surface or zoneWhere the combustion is wantedexceedsi th-eyitate of. propagation ofinflammation vof-the mixture, 1 Back-flash may be prevented in two '-ways :'(a) by'the cooling'action'of. thewalls of'passagesthrough which--themixtur e flows, as when the -mixture is i caused to flow throughaflsmall tube or narrow slit or other smallopeningforamulti .plicity ofthese, one common form of means for preventing back flashin this Waybeing the wire gauze screen, andanother being porous diaphragm of largeenough fheat'ab sorbing' and dissipating capacity; and '(b) I by causingthe mixtureto approach the com- Specification of Letters Patent:Application filed September 21, 1912. Serial No. 721,557. 7

Patented July 13, 1915.

bustion zone with a velocity greater than the rate of propagation-ofinflammation. On the other hand, to prevent blow-off and to localize theflame cap or combustion surface at the desired place or combustion zone,the

velocity with which the mixture is moving at the combustion zone mustnot-exceed the rate of propagation of inflammation. Continuous andlocalized combustion of explo-' I ture to flow with a velocity greaterthan the 7' rate of propagation of inflammation and then reducing thevelocity to the rate of propagation of inflammation and preventingdissipation of the-mixture or. diffusion with other gas, and burning themixture at the surface at which the velocity becomes equal to the rateof propagation of inflammation. The first of these two'ways, that is, bythe use of a flame-interrupting, cooling screen or partition, is oflessefliciency than the second and is of limited application because themaxlmum rate of combustion cannot be attained and because of thedifficulty of preventing the feed passage way or screen from becomingheated and losing'its flame-inter: rupting property. v The presentinvention relates to the second Way of securing continuous and localizedcombustion of explosive gaseous mixtures.

In Letters Patent No.' 755,876, granted to .me March 22nd, 1.904, 'Ihave described and claimed the method-of burning explosive gaseousmixturesin this way which consists in causing the mixture j to move witha velocity greater than the rate of propagation of inflammation throughthe mixture and then reducing the velocity to the rate of propagation ofinflammation and preventing.

difi'usionWith-other gases by causing the mixture to. spread out so thatthe successive surfaces of 'uniformvelocity shall have adjacent pointsin any such-surface at substantially thefsame distance from the placeWhere thespreading begins and burning the mixture at'the' surface at'.which the velocity. is equal to the rate of propagation of inflammationp In burning explosive mixtures in accordancev with the presentinvention, the mixture is caused to flowin one,or a number of jets or,streams with a velocitygreater than: the rate of propagation .ofinflammation through the mixture and while flowing unconfined toimpingeupon the face' of a freely porous and permeable 'bed of suitablematerial, whereby it is caused tospread out laterally with loss ofvelocity and to enter or tend to enter the pores or passages of the faceof the bed, the degree of porosity of the bed, and the velocity withwhich the mixture is moving and the'size' and character of the jet orjets, andwill either burn at the surface of the bed or enter and flowthrough the pores or passages of the bed before burning a greater'orless distance ac-' cording to the character ,of the explosive mixture,the permeability of the bed, and the-velocity, size and characterof theimpinging jet or jets. Ifthe velocity of flow of an impinging jet issufliciently great, the mixture after spreadingat the surface of v thebed and havingfits velocity thereby reduced will enter the bed tohave-its velocity still further reduced as it advances through the beduntil it reaches a surface or zone at which the velocity of flow equalsthe rate of propagation of inflammation and at which the combustion willbe located, the products of combustion then escaping through the bedbeyond the surface of combustion or flame cap; and if the velocity offlow is great enough and the bed thin enough the flame cap may belocated at or adjacent to the rear surface of the bed. If, however, thevelocity of the impinging stream of mixture is such that equalitybetween the rate of propagation of inflammation and flow velocity of themixture is attained at the surface of the" bed against which, the mix-.

ture impinges, then the flame cap or surface of combustion will locate.closely against or partly within the superficial layer of the bed, theproducts of-combustion as before passing onward through the pores orpassages of the bed. In such case the bed need not be of a character tocause gases flowing through it to expand and lose velocity, but needonly be of a character to provide for theescape therethrough of theproducts of combustion, and need not be of any considerable thickness, acomparatively thin perforate, or porous diaphragm or plate beingsometimes suflicient; If, however,

; ized at the impact surface.

the surface of combustion or flame cap is.

to be located withinthe bed or at the rear surface thereof, the bedshould be. of such a character, either by having intercommunieatingpassages or expanding passages, or passages which are both expanding andin tercommunicating, that the mixture will be caused to spread out andhave its velocity reduced as it advances through the -bed. A bed ofbroken or other granular refractory material with the pieces eitherloose or bonded meets the requirements, whether-the combustion is to belocated within or at the rear surface of the bed or. atthe near orimpact surface of the bed. v 0 The invention finds its greatestadvantage for some purposes when the flow of the mix tureis regulated tolocate the combustion at the impact surface of the bed. With the freeescape of the gases of combustion through the bed beyond the impactface, and if thesurface of the bed is of a proper character, theoutwardly facingsurface of each part and particle of the face of thebed. will be actually or. practically in contact with a part of theexplosive mixture at the time when its velocity has been reduced'to therate of propagation ofinflam'matiomso that combustion willtakeplace-against such face. The interposition of unburnt or burnt gasesbetweenthe surface and the burning gas is thus avoided, and thetemperature of all parts of the surface of the impact face,- of the. bedis raised/to the highest value physically possible so that it becomeshighly incandescent, radiating both heat and light to a high degree. Ifthe combustion is located at or near the rear surface of the bed,

such rear surface will then be'incandescent' and radiate heatand light,butit'will not become so highly incandescent as does the impact surfacewhen the combustion is local- Ifthe bed be extremely thin, the rearsurface may be so close to the impact surface as to eliminate anydistinction with regard: to the location v of the flame cap at one ortheother and both will be highly incandescent, radiating both heat andlight.

Burning the 'mixture at the impact face v of"thebed is included in themethod claimed broadly herein,'but the method of burning the mixture atthe impact surface as distinguished from burning the mixturewithin thebed as claimed specifically herein forms the subject matter of'anapplication filed by me on the 21st day of September,

1912, Serial No. 721,558. It should be noted that whether the coinbustion is located at the impact surface or beyond, the heating of theadvancing mixture as it'approaches the surface :of combustion tends toincrease the rate of propagation of inflammation, and a similaracceloration of the rate of combustion is believed 30 to be contributedby the incandescent solid matter; thus promoting the attainment ofequality between the rate of propagation and flow of velocity, andincreasing the amount of mixture that can be burned at a givensurfaceand Within a given space.

The impact bed of an apparatus for use in practising my method may be ofany suitable character or construction to provide the necessary pores orpassages for the escape of the products of combustion, and for spreadingthe gaseous mixture when the combustion is to be'located within or atthe far side of the bed, and may be of any suitable material. For alasting or permanent bed, a suitable refractory material,

- that is, one which will withstand the degree of heat to which it issubjected, must be used. The degree of porosity and permeability of thebed should be such, if the combustion is to be located within the bed,as to permit the desired amount of mixture to enter and flowtherethrough within the de-- sired extentof the bed; and if combustionis to be located at the impact surface there should be such a degreeof'porosity and permeability as will permit with a given rate of feed ofmixture the combustion of that mixture substantially in contact with allof the physical surface over which the advancing stream spreads. Asbefore stated, if the combustion is to be located within the bed or atthe far facethereof, the bed should be formed to cause the mixture tospread out and lose velocity as it advances through the bed, being forthis purpose formed with inter-communicating or expanding passages forthe gas flowing therethrough, or with passages both inter-communicatingand -expanding;'- but, on the other hand, if the. combustion is to belo-' cated at the impact surface of the bed, the passages through thebed need be only of such character as to provide for the free escape ofthe products of combustion and.

need not therefore be inter-communicating or expanding. The surface ofthe bed, if the combustion is to be located against the impact surface,and preferably. in all cases, should be of such a character, or have itssurface particles or parts so shaped, as to promote proportionatepassage of the mixture between the parts or particles and to prevent tothe greatest degree the retention of a dead layer of gas on the sidetoward which the mixture is advancing. The shape of the impact face ofthe bed will vary according to the character and shape of the jet orjetsof mixture caused to impinge thereon. On the other hand, the-bed maybe of various shapes according to the purpose to which the invention is,to be applied, and a single bed or a number of beds suitably grouped andarranged may be employed, the character and arrangement ofthe jets ofvided state in proper proportions,- that is, in

proportions such that the mixture will have the property ofself-propagation of inflammation. For producing the highest temperature,the oxygen should be undiluted and the mixture should contain oxygen andcombustible matter in chemical combining proportions at the time ofcombustion; but there may be an excess of either the combustible matteror the combustion supporting gas within the limits which determine theproperty of self-propagation. The mixture may be varied in this respectaccording to the desired character of the products of combustion, thatis, whether it is desired that theproducts shall be neutral, oxidizingor reducing. Also, the mixture may of course contain neutral gas such asnitrogen, carbon dioxid or water vapor,

so long as the amount of such neutral gas is not sufficient to make themixture nonexplosive. w The accompanying drawings illustrate simpleforms of apparatus adapted for'carrying out my improved method.

In said drawings: Figure 1 shows a simple form of single jet apparatuspartly in section. Fig. 2 is a similar view of another illustrative formof apparatus; Fig. 3 is a sectional view illustrating a further,modified form of apparatus; Fig. 4: is a similar view of another form ofapparatus; Fig. 5 is a similar view of a form of apparatusin whichthefuel and combustion supporting gas are supplied from separate nozzles;Fig. 6 is a similar view of an apparatus having a, thin sheet; Fig. 8 isa section taken on line 8 of Figs. 6 and 7. Fig. 9 isa face view of adevice for supplying a plurality of jets of the explosive mixture.

Referring first to Fig. 1, 10 represents a porous and permeablecombustion support '20 ing bed against which a jet or stream of theexplosive mixture is directed by a dischargevvPipe or nozzle 11. The ixtbe v y supplied to the nozzle 11 from any suitable source or by any.suitable means, as for ex-..

ample, by the means shown, by which a mixture of a fuel gas and acombustion sup porting gas is supplied, and the mixture should be.supplied under sufiicient pressure to cause the jet or stream issuingfrom the,

nozzle to move toward the bed with a Vebustion supporting gas, the fuelgas and combustion supporting gas being supplied to vthese tanks bysuitable means adapted to maintain the desired pressure therein. Anoutlet leads fromeach tank controlled by valves (1 and g respectively,and from these outlets .a supply pipe 12 leads to-the discharge pipe ornozzle 11. The valves (1. and

g serve to control the proportions of fuel gasand combustion supportinggas in,the mixture, and the velocity of flow of the -mixture from thenozzle 11 mayalso be con-- trolled by these valves. The properproportions of fuel gas and combustion sup; porting gas, that is,proportions such according to the nature of the constituentgases thatthe mixture will have the property of self-propagation of inflammation,may be readily determined by experiment. When the jet I or stream ofmixture issuing from the nozzle 11 strikes the face of the, bed 10 itwill spread out or mushroom and lose a part of its velocity,

' and, if still unburned, will then enter and flow through the pores orpassages of the bed and escape therefrom. at points deter mined by thecharacter and shape-of the bed, the velocity'of the flowbeingcontinually decreased as the distance from the im-' mit the gaseousmixture to expand or spread pact face of the bed increases provided thebed is ofv such a character as to cause or perout laterally as itadvances through the bed. When the mixture is ignited the flame cap orsurface. of combustion will locate where the velocity of flow is reducedto the rate of propagation of inflammation; By properly I adjusting thesupply ofmixtureby means of the valves (1 and g to control the velocityof the jet issuing from the nozzle 11, the

flame cap or surface of combustion may be caused to locate, as alreadyexplained, either i at or against the impact face (i of the bed,

or within the bed at a greater or less distance beyond the impact face,as indicated, for

example by the dotted lines 6 and 7. The

location of the flame cap, and also the amount of spreading of themixture atthe face of the bed, might also becontrolled by moving thenozzle-toward and away from the bed. Whether located at the impa face orwithin the bed, the greater part of the products of combustion will passon through the pores or, passagesof the bed to escape from apart of thesurface of the.

bed other than the impact face through which the jet or stream ofmixture enters.

As there isa very considerable reduction in the flow velocity of themlxture when it strikes and spreads out over the impact-face located atthe impact face under quite con-1 of the bed, the combustion will remainf siderable variations in the velocity of the im pinging jet, so that anextremely accurateadjustment of the velocity or rate of supply of thegas is not-necessary in order tov maintain the combustion in .thisposition. It

should be noted that if the explosive mixture should contain an excessof fuel beyond what i will combine with the oxygen in the mixtureas itreaches thecombustion zone, the unconsumed fuel will pass on from thecombustion zone with the products of combustion andwill burn at andbeyond the exit face of the bed or wherever it may besupplied withadditional oxygen from the atmosphere; or otherwise. It might also benoted here that some air may be entrained by the jet between I thenozzle and the bed, so that the mixture may contain a somewhat greaterproportionate amount of air when it reachesthe 1 bed than it has at thenozzle. In order that the combustion zone or surface may co-incide,

more or less accurately with the impact face of the bed throughout thegreatest possible or a considerable extent of the impactface,

the impact face should-be shaped according to the character of the jet.With a single I solid jet issuing from a cylindrical orifice,

and-with the mixture impinging at substan bed, the impact face should beof a suitable tially right angles against the faceof the 7 circular"concave shape as'indicated: by this figure. It is also desirable to'have the. im-- pact face of. the bed so shaped when the roe combustionis tobe. located within the bed since the flame cap or. surface ofcombustion will'then be caused-to take a more flattened v if a solidcylindrical jet were caused to "or spread; out shape than would be thecase 1 strike against an impactfbed' having a generallyflat surface v InF ig.- 1. I have,shown the combustion supporting bed as formed of amassof loose broken or other Igranular refractory ma: terial, such as chromeore, alundumor magnesite, in a suitable container 14. If a com'fparatively weak mixture is to be burned,

pieces of fire brick of suitable sizemay be" used. With such a bed theproducts of combustion-will escape from portions of the upper surface ofthe bed other than the impact face, as indicated by the arrows, or thereceptacle 14" might be made with outlet openings 15 as indicated bydotted lines,

. Fig. 2 shows also a singlenozzle for dis- 7 charging a solid jetagainst aporous and permeable combustion supporting bed havq ing aconcave impact face. As shown in this figure, however, the bed hasitsrear or far surface open so that the products ofcombustion may escapetherefrom as indicated by the arrows. Such a'bed or diaphragm open onboth sides maybe formed in'any suitable manner, as for example, bybonding together in a mold or otherwise pieces of granular refractorymaterial, or by molding a plastic mass to which has been added matterwhich on being heated will disappear and leave a suitably porous andpermeable bed or diaphragm. With this'bed, the combustion may be locatedas before described either at the impact face or within the bed bysuitably adjusting the velocity of the impinginggjet, and if thevelocity of the jet is sufliciently great the flame cap or surface ofcombustion may be caused to locate at, or close to, the rear surface ofthe bed so as to cause such rear surface to become heated toincandescence and to radiate both heat and light, though not to the samedegree as the near or impact face when the flame is lo cated at suchnear or impact fact. When the rear face of the bed is to be heated toserve as a radiating surface by having the combustion located at or nearit, 'it will best be shaped according to the character and arrangementof the impinging jet or jets; for example, with a single solid jet therear surface of the bed should be of a more or less convex form as shownin Fig. 2 so as to correspond in shape more or less closelywith theshape of the flame cap or surface of combustion. Fig.

2 also shows means for supplying an explosive mixture of sprayed oratomized oil and air. Oil is supplied through a pipe 16 to anatomizingdevice 17 to which air under pressure is supplied through pipe18 and from which the atomized oil mixed with air is discharged into achamber 19 from which the mixture of oil and air passes to the nozzle 11to be discharged against the bed 10. The pipe 18 is connected with asuitable tank or other source of supply of air under pressure, and apipe leading from the pipe 18 directly to the mixing chamber 19 isprovided for supplying additional air to the mixture in the mixingchamber 19. Valves 21 and 22 control the supply of air to the atomizingde ice and the supply admitted directly to the mixing chamberrespectively. Connections might obviously be -provided for supplying anumber of discharge nozzles with mixture from the chamber 19, and othersuitable devices might be used for supplying an explosive mixture ofsprayed or atomized oil fand air or other combustion supporting gas. Ina similar manner an explosive gaseous mixture of air and coal dust orcharcoal dust might be burned.

' moving with alower velocity and its outer portion with highervelocity. For receiving such a jet the impact face of the bed instead ofbeing concave should be of a general convex form as shown in this figurein order that the velocity of the mixture at the impact face may besubstantially uniform or more nearly so than would be the case if such ajet were discharged against a fiat or concave bed. Also, the bed shownin this figure is intended for combustion at the impact face only, thepores or passages through the bed having a substantially uniformcapacity or cross area from the impact face to the rear surface of thebed, and being thus adapted to serve to carry away the products ofcombustion but not to cause a gradually decreased velocity of gasflowing through them.

Fig. 4 also shows a porous bed having noncommunicating passagesextending through the bed from the impact face to the rear surface, butas shown in this figure the passages increase in size from the impact tothe rear surface of the bed, such expanding passages allowing gasflowing through them to expand so as to advance in increasing volume andwith. decreasing velocity. A bed of this form is therefore adapted notonly for combustion at the impact face, but also adapted for use when itis desired to have the combustion locate beyond the impact face withinthe bed. With a bed of this kind, how- 'ever, localized combustionwithin the bed cannot be maintained under such wide variations in theflow velocity of the mixture entering the bed as with a bed havingsuitably formed inter-communicating passages such: as are secured byforming the bed of suitable sized pieces of broken material.

Fig. 5 illustrates an apparatus in which a the fuel gas or other form offuel and the combustion supporting gas are supplied separately fromsupply pipes or nozzles 22 and 23 respectively, set so that the jets orstreams of fuel and combustion supporting gas respectively will meet ator before reaching the impact face of the bed to form an explosivemixture which, driven by the force of one or both of the jets, spreadsout and burns at the surface of the bed or within the bed as before.This form of apparatus'nia-y be used where the fuel is in the form ofgas, but is especially adapted for use when oil or other liquid fuel issupplied in the form of a jet or spray to be vaporized as it reaches orapproaches the impact surface of the bed where the combustion islocated,the vapor then mixing with the air or other combustionsupporting gas and spreading out therewith over the surface of, the bedto be burned. I I As before stated, jets of various forms, and anydesired number of jets arranged in various ways, may be employed inconnec tion with suitably shaped and arranged pomug and permeable beds.Fig. 6 shows a multiple jet nozzle 25' for supplying a row ranged todischarge radial or diverging jets,

of jets, and Fig. 7 showsa nozzle 26' hav-' ing an outlet slot forsupplying the mixture 7 6 or Fig. 7. Fig. 9 shows a face view of anozzle or supply chamber having a number of discharge openings ornozzles distributed over its surface. The porous bed receiving the jetsdischarged from such a device, if the jets were parallel jets all of thesame size and velocity, would best have a plain impact face bounded by araised edge portion; If, however, the central or inner dischargeopenings or nozzles were made larger than the outer ones so. as tosupply jets of greater energy, or if the nozzles. were arthen the impactface of the combustion bed i shouldhave a more generally rounded concaveform, while if the inner jets were less' powerful than the outer ones,the bed should best have an impact face of convex form.

-What is claimed is:

1. The method of burning explosive gaseous mixtures, which consists insupplying the mixture continuously and driving it unconfined toward thesurface of a porous and permeable bed whereby the velocity is reduced,and'burning the mixture where the velocity is equal to the rate ofpropagation of inflammation through the mixture, and permitting theproducts of combustion to escape through the passages of the bed.

2. The method of burning explosive gaseous mixtures which consists insupplying the mixture continuously and driving it unconfined toward thesurface of a porous and permeable bed whereby the velocity is reduced,then further reducing the velocity to the rate of propagation ofinflammation by causing the mixture to spread as it advances through thebed beyond the impact face of the bed, and burning the mixture where thevelocity is equal to the rate of propagation of inflammation andpermitting the products of combustion to escape through the passages ofthe bed.

3, The method of burning explosive gaseous mixtures which consists incausing the mixture to flow unconfined with a velocity .greaterthan therate of propagation of inflammat1on-through the mixture, and thenreducing the velocity to the rate of propagation of inflammation byinterposing in the the bed.

I 4. The method of burning explosive gaseous mixtures which consists incausing the. I

mixture to, flow unconfined with a velocity greater than the rate' ofpropagation of inflammation through the mixture, then reducing thevelocity by causing the mixture to flow against the surface of a porousand permeable bed of refractory material, then further reducing thevelocity to the rate of propagation of inflammation by causing themixture to spread as it advances through the bed beyond the impactsurface of the bed, and burning the mixture where the velocity is equalto the rate of propagation of inflammation and allowing the products ofcombustion to escape beyond the combustion zone. 5. The; method ofproducing heat, which consists in combining a fuel in a finely dividedstate with a combustion supporting gas in proportions to form anexplosive gaseous mixture, and driving the explosive mixture thus formedunconfined at a velocity.

greaterv than the rate of propagation of inflammation of the mixtureagainst the surface of a porous and permeable bed of refractory materialthe temperature of which is sufiicient to cause ignition of saidmixture, and thereby heating and igniting the mlxture.

6. The method of producing heat, whi-c consists in combining a fuel ina, finely divided state with a combustion supporting gas in proportionsto form an explosivegaseous mixture, driving theexplosive mixturepermitting, the products of combustion to escape through the passages ofthe .bed.

' In testimony whereof I have hereunto set my hand in the presence oftwo subscribing witnesses.

I CHARLES E. LUOKE.

Witnesses:

FRANK C. ERB,

IA.L.KENT.

